Various CuO-based sorbents were prepared to investigate effects of sorbent ingredients such as SiO2, MnO2, and MoO3 on desulfurization reactivity. Several candidate sorbents chosen from a TGA screening test were further tested in a microreactor system. The amount of SiO2 support to minimize sintering of sorbents was 25 wt%. Sulfur loading was seriously affected by the amount of additives (MnO2, MoO3) in a multi-cycle test. Improvement of sulfur loading by the additives was observed in the multi-cycle test. Effects of support materials on sulfur loading were also investigated by using SiO2, gamma -alumina and zeolite. SiO2 showed the best performance among the support candidates. The sorbent showing the best sulfur loading ability was CMS6 (CuO:MoO3:MnO2: SiO2=61 :11 :3 :25). Its sulfur loading reached up to 13.8 g sulfur/100 g sorbent in a multi-cycle test.